Activity Outlook

Weekly Meteor Activity Outlook articles by Bob Lunsford. Bob gives outlooks to upcoming meteor activity about once a week. He features showers from the working list of meteor showers as well as suspected radiants. Please refer only to the radiants of the Working list of visual meteor showers in observing reports.

Meteor Activity Outlook for October 18-24, 2008

Meteor activity in general increases in October when compared to September. A major shower (the Orionids) is active most of the month along with several minor showers. Both branches of the Taurids become more active as the month progresses, providing slow, graceful meteors to the nighttime scene. The Orionids are the big story of the month reaching maximum activity on the 21st. This display can be seen equally well from both hemispheres which definitely helps out observers located in the sporadic-poor southern hemisphere this time of year.

During this period the moon reaches its last quarter phase on Tuesday October 21st. At this time the moon will rise near 0100 local daylight time and will remain in the sky the remainder of the morning. This weekend the waning gibbous moon will make meteor watching difficult. Some slow meteors may be glimpsed during the evening hours before the moon rises, but rates at this time of night will be low. The estimated total hourly rates for evening observers this week is near six for those located in the mid-northern hemisphere (45 N) and three for those viewing from the mid-southern hemisphere (45 S). For morning observers the estimated total hourly rates should be near twenty five for those located in the mid-northern hemisphere (45 N) and fifteen for those viewing from the mid-southern hemisphere (45 S). Locations between these two extremes would see activity between the listed figures. These rates assume that you are watching from rural areas away from all sources of light pollution. The actual rates will also depend on factors such as personal light and motion perception, local weather conditions, alertness and experience in watching meteor activity. Morning rates are reduced due to moonlight.

The radiant positions and rates listed below are exact for Saturday night/Sunday morning October 18/19. These positions do not change greatly day to day so the listed coordinates may be used during this entire period. Most star atlases (available at science stores and planetariums) will provide maps with grid lines of the celestial coordinates so that you may find out exactly where these positions are located in the sky. A planisphere or computer planetarium program is also useful in showing the sky at any time of night on any date of the year. Activity from each radiant is best seen when it is positioned highest in the sky, either due north or south along the meridian, depending on your latitude. It must be remembered that meteor activity is rarely seen at the radiant position. Rather they shoot outwards from the radiant so it is best to center your field of view so that the radiant lies at the edge and not the center. Viewing there will allow you to easily trace the path of each meteor back to the radiant (if it is a shower member) or in another direction if it is a sporadic. Meteor activity is not seen from radiants that are located below the horizon. The positions below are listed in a west to east manner in order of right ascension (celestial longitude). The positions listed first are located further west therefore are accessible earlier in the night while those listed further down the list rise later in the night.

The following showers are expected to be active this week:

At this time of year debris from comet 2P/Encke produces a double radiant very close to the position of the antihelion radiant. From now through the end of November, it is impossible to resolve the antihelion meteors from those produced by comet 2P/Encke. Therefore we suggest that observers simply classify meteors from this area as either north or south Taurids. Although the radiants actually lie in Aries during October, they reach maximum activity in November when they are situated in the constellation of Taurus.

The center of the large Northern Taurid (NTA) radiant is now centered at 02:28 (037) +18. This position lies in central Aries, six degrees southeast of the second magnitude star Hamal (Alpha Arietis). The center of the large Southern Taurid (STA) radiant lies at 02:36 (039) +12. This position also lies in southern Aries, twelve degrees southeast of the second magnitude star Hamal (Alpha Arietis). The two radiants are separated by slightly over five degrees. Since they have nearly the same right ascension (celestial longitude), it is difficult to distinguish meteors that move north or south out of the radiants. It is less difficult to distinguish those meteors traveling east or west. These radiants are best placed near the meridian at 0200 LDT. At 29 and 27 km/sec., the average Taurid meteor travels slowly through the skies.

Sirko Molau's new studies of video radiants has revealed that the Northern Taurid's reach two plateaus of activity with the first occurring on October 20th. The moon will subdue this activity so it will most likely not be noticed. The same study has revealed that the Southern Taurids may peak near October 11 and that the activity for this shower will remain fairly constant through the first week of November. After that rates will dwindle until these meteors disappear near the end of November.

The Orionids (ORI) peak on the morning of October 21st from a radiant located at 06:20 (95) +16. This position lies in extreme eastern Orion, four degrees west of the second magnitude star Alhena (Gamma Geminorum). The radiant rises near 2300 LDT and is best placed on the meridian near 0500. At 66km/sec., the average Orionid is swift. A detailed discussion of the Orionids with charts is presented on the AMS website at: http://www.amsmeteors.org/showers.html#ORI

The Epsilon Geminids (EGE) peak on October 18 radiant with a average ZHR of only two. Rates near maximum can vary sometimes reaching in excess of five. The radiant is currently located at 06:56 (104) +27. This position lies in central Gemini, three degrees northeast of the third magnitude star Epsilon Geminorum. Current rates will be most likely less than one per hour, especially with the bright moon in the sky. At 70km/sec., the average Epsilon Geminid is swift. Sirko Molau's new studies of video radiants has also revealed that the Epsilon Geminids may peak as late as October 21st.

Sirko Molau's studies of video radiants has revealed activity in northern Cancer between October 10 and November 4, peaking on the October 14th. The radiant for the Iota Cancrids (ICA) lies at 09:00 (135) +29. This position lies two degrees east of the fourth magnitude star Iota Cancri. Visual activity is expected to be low, especially with the bright moon in the morning sky. The radiant rises near 0200 LDT and is best placed high in the east during the last dark hour of the morning. At 67km/sec., the average Iota Cancrid will appear move swiftly through the skies.

Another radiant discovered during Sirko Molau's studies of video radiants Is the Tau Ursa Majorids (TUM). This shower is active between October 15th and the 22nd, peaking on the 16th. The radiant lies at 09:36 (144) +65. This position lies in western Ursa Major near the faint star 23 Ursae Majoris. Again visual activity is expected to be low with the bright moon in the morning sky. The radiant is circumpolar north 25 degrees north latitude and is best seen during the last hour before dawn when it lies highest above the horizon in a dark sky. At 54km/sec., the average Tau Ursa Majorid meteor will appear move swiftly through the skies.

The Leo Minorids (LMI) are active from October 17-27 with maximum activity occurring on October 23rd. ZHR's are usually low but the radiant is far removed from the Orionids and Epsilon Geminids so that any possible shower members should be easily identified. This radiant is currently located at 10:28 (157) +39, which places it on the Leo Minor/Ursa major border, just south of a pair of third magnitude stars known as Mu and Lambda Ursae Majoris. The radiant is best placed just before dawn when it lies highest in a dark sky. This shower is better situated for observers situated in the northern hemisphere where the radiant rises far higher into the sky before the start of morning twilight. At 62km/sec., the average Leo Minorid is swift.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately twelve Sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near four per hour. As seen from the mid-southern hemisphere (45S), morning rates would be near four per hour as seen from rural observing sites and one per hour during the evening hours. Locations between these two extremes would see activity between the listed figures. Morning rates are reduced during this period due to the bright moon.

The table below presents a summary of the expected activity this week. Rates and positions are exact for Saturday night/Sunday morning but may be used all week.

SHOWER DATE OF MAXIMUM ACTIVITY CELESTIAL POSITION ENTRY VELOCITY CULMINATION HOURLY RATE CLASS*
    RA (RA in Deg.) DEC Km/Sec Local Daylight Time North-South  
             
Northern Taurids (NTA) Nov 12 02:28 (037) +18 29 02:00 2 – 2 II
Southern Taurids (STA) Nov 05 02:36 (039) +12 27 02:00 3 – 3 II
Orionids (ORI) Oct 21 06:20 (95) +16 66 06:00 5 - 5 I
Epsilon Geminids (EGE) Oct 18 06:56 (104) +27 70 06:00 <1 - <1 II
Iota Cancrids (ICA) Oct 14 09:00 (135) +29 67 08:00 1 – <1 IV
Tau Ursa Majorids (TUM) Oct 16 09:36 (144) +65 54 09:00 <1 – <1 IV
Leo Minorids (LMI) Oct 23 10:28 (157) +39 62 11:00 1 - <1 II

Meteor Activity Outlook for October 11-17, 2008

Meteor activity in general increases in October when compared to September. A major shower (the Orionids) is active most of the month along with several minor showers. Both branches of the Taurids become more active as the month progresses, providing slow, graceful meteors to the nighttime scene. The Orionids are the big story of the month reaching maximum activity on the 21st. This display can be seen equally well from both hemispheres which definitely helps out observers located in the sporadic-poor southern hemisphere

Meteor Activity Outlook for October 4-10, 2008

Meteor activity in general increases in October when compared to September. A major shower (the Orionids) is active most of the month along with several minor showers. Both branches of the Taurids become more active as the month progresses, providing slow, graceful meteors to the nighttime scene. The Orionids are the big story of the month reaching maximum activity on the 21st. This display can be seen equally well from both hemispheres which definitely helps out observers located in the sporadic-poor southern hemisphere

Meteor Activity Outlook for September 27-October 3, 2008

Meteor activity in general increases in October when compared to September. A major shower (the Orionids) is active most of the month along with several minor showers. Both branches of the Taurids become more active as the month progresses, providing slow, graceful meteors to the nighttime scene. The Orionids are the big story of the month reaching maximum activity on the 21st. This display can be seen equally well from both hemispheres which definitely helps out observers located in the sporadic-poor southern hemisphere

Meteor Activity Outlook for September 20-26, 2008

September offers longer nights and cooler temperatures in the northern hemisphere. In the sky, no major showers are visible from either hemisphere but the northern hemisphere enjoys the advantage of higher sporadic rates. The two recognized minor showers active in early September have high northern declinations (celestial latitude) therefore are much better suited to be viewed from locations north of the equator. Toward the end of the month the antihelion radiant becomes entangled with the two Taurid radiants and it is

Meteor Activity Outlook for September 13-19, 2008

September offers longer nights and cooler temperatures in the northern hemisphere. In the sky, no major showers are visible from either hemisphere but the northern hemisphere enjoys the advantage of higher sporadic rates. The two recognized minor showers active in early September have high northern declinations (celestial latitude) therefore are much better suited to be viewed from locations north of the equator. Toward the end of the month the antihelion radiant becomes entangled with the two Taurid radiants and it is